ceview writes: The speed of light appears to be not constant at a quantum level. It may appear to be dependent more on the electric charge of the vacuum. Also published in the European Physical Journal D http://epjd.epj.org/ Does this really have implications to GPS, quantum gravity?
"'Tis true, 'tis pity, and pity 'tis 'tis true."
-- Poloniouius, in Willie the Shake's _Hamlet, Prince of Darkness_